Looper mechanisms for sewing machines



May 5, 1959 H. HACKLANDER 2,884,884

LOOPER MECHANISMS FOR SEWING MACHINES Original Filed Dec. 19, 1955 2 Sheets-Sheet 1 7* T \7 i 1 I i .1 :2!

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INVENTOR Hans Hack/under A T'TQQNEY May 5, 1959 H. HACKLANDER LOOPER MECHANISMS FOR SEWING MACHINES Original Filed Dec. 19, 1955 2 Sheets-Sheet 2- INVENTOR Hans Hack/cinder TORNEY United States Patent 2,884,884 LOOPER MECHANISMS FOR SEWING MACHINES Hans Hacltlander, Wanen'Township, N.J., assignor to TheSinger Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Original application December 19, 1955, Serial No. 553,806. Divided and this application March 26, 1957, Serial No. 648,528

1 Claim. (Cl. 112-199) The present invention relates to a looper mechanism for sewing machines and has for a primary object to provide means for facilitating adjustment of the loop seizing elements, which means is simple and economical, accurate, dependable, easy to operate, durable, and will not interfere with the stitch-forming operation. At the same time, it is an object of this invention to provide a loop taker adjustment means which is adapted for use with modern high speed sewing machines where, because of the high speed, balance and vibration and noise as well as wear become very important.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. l is a vertical sectional view substantially through the center of a sewing machine embodying the present invention.

Fig. 2 is a horizontal sectional view taken substantially on the line 22 of Fig. 1.

Fig. 3 is a horizontal sectional view taken substantially on the line 3-4 of Fig. 1.

Fig. 4 is a fragmentary detail view, partly in section and partly in elevation, of the looper mounting and adjustment means constructed in accordance with the present invention.

Fig. 5 is a detail view in elevation illustrating the mounting of the looper on the looper clamp.

The present invention is herein illustrated and described as embodied in the sewing machine that forms the subject matter of my prior application, Serial No. 553,806, filed December 19, 1955, from which this application has been divided.

With reference to the drawings there is illustrated a sewing machine having a frame 1 including a vertically disposed hollow standard 2 carrying a laterally extending bracket arm 3. The hollow interior of the standard 2 comprises an oil-tight splash-lubrication compartment 4 which is closed at the top by a horizontal partition 5 in the frame and closed at the bottom by a base plate 6.

A vertical axis main shaft 7 is journaled for rotation in the lubrication compartment 4 of the standard 2 in an upper bearing bushing 8 secured in an aperture in the partition 5 and in a lower bearing bushing 9 carried by a lug 10 on the standard 2. At its upper end, the main shaft 7 extends through the upper bushing 85 to the exterior of the frame where it receives a hand-wheel 11. The main shaft 7 is held against vertical movement by a collar 12 and the hub of a gear 13 which engage the upper and lower ends, respectively, of the lower bushing 9. The gear 13 meshes with a similar gear 14 on a horizontal axis drive shaft 15 journaled in the lubrication compartment 4 in bearing bushings 16 and 17. The bushing 16 is secured in a lug 18 on the standard 2 and the bushing 17 is secured in a partition 19 of a belt compartment 28 that is separated from the lubrication compartment 4. The drive shaft 15 extends through the bushing 17 into the belt compartment 20 where it receives belt pulley 21 by means of which power is delivered to the machine.

The stitching mechanism of the machine includes a needle bar 22 mounted horizontally for longitudinal reciprocation in a bushing 23 in a flat front wall 24 of the standard 2, and carrying a needle 25 at its outer end. Longitudinal reciprocation is imparted to the needle bar 22 by a pitman 26 pivotally connected at one end to the needle bar and at the other end to a crank 27 on the main shaft '7. Cooperating with the needle 26 in the formation of stitches is a thread-carrying looper 28 secured by a screw 29 to a looper carrier or clamp 38 having a hub 31 that is mounted upon the end of a looper shaft 32 and is split at the end to be clamped to the shaft by a screw 33. The looper shaft 32 is journaled for oscillation in a bushing 34 extending through 2. lug 35 in the wall 24 of the'standard and is arranged in a horizontal plane with the axis thereof at an acute angle to the extended axis of the needle bar 22 when viewed in top plan as shown in Fig. 2. The looper shaft 32 is held against endwise sliding in the bushing 34 by a retaining collar 36 which abuts against the outer end of the bushing and the hub of a crank arm 37 on the shaft 32. The crank arm 37 carries a ball-end crank pin 38 that is connected to one end of a pitman 39 that, at its other end, has a strap portion embracing an eccentric 419 on the main shaft 7.

In order to obtain the proper cooperation during stitch formation between the looper 28 and the needle 25, the looper 28 is mounted for universal adjustment. Adjustment of the looper 28 radially relatively to the looper shaft 32 is provided in the usual manner by a slot 29a in the shank of the looper .28 through which slot the screw 29 extends, and adjustment of the looper 28 longitudinally of the looper shaft 28 and circularly about the shaft is provided by backing off the screw 33 to release the clamp 30 for movement relatively to the looper shaft 32.

In accordance with the present invention, there is provided means for facilitating the adjustment of the looper longitudinally and circularly about the looper shaft 32. Toward this end, there is provided a reference sleeve or collar 41 on the outer end of the looper shaft 32, which collar is releasably secured to the shaft by a set screw 42. An escutcheon 43 surrounds the bushing 34 and that portion of the shaft 32 adjacent to the collar 38 as well as the inner end of the collar 41. The escutcheon 43 is secured to the bushing 34 by a set screw 44. To adjust the looper 28 axially on the shaft 32, it is necessary only to release either the hub 31 of the looper clamp 30 or the collar 41 from the looper shaft 32, depending upon the direction in which the looper is to be adjusted, slide the released element into the desired position while using the other of the two elements as a reference and securing it in place, and thereafter, releasing the other element, moving it into its normal position relatively to the adjusted element and securing it in place. For example, if it were determined that the looper 28 had to be moved inwardly axially of the shaft 32 by fivethousandths of an inch, the set screw 42 is backed oif to release the collar 41 which is then moved the required distance from the end of the hub 31. The hub 31 is still secured to the shaft and serves as a stationary reference point from which the required distance can be measured, as by a feeler gauge. When properly positioned, the collar 41 is secured to the shaft 32 and the Q hub 31 is released from the shaft, moved up against the collar 41 and secured in this position. Also, if it is desired to turn the looper circularly about the shaft 32, it is necessary only to loosen the clamp 31 by backing ofi the screw 33 and turn it and the looper 38 carried thereby the required amount, the collar 41 functioning to retain the looper in its proper position lengthwise of the shaft. Of course, when the looper clamp 65 is removed, the collar 41 will remain to indicate the proper setting when it is replaced.

Cooperating with the needle 25 and looper 28 is a third thread handling element, which, in view of the fact that the illustrated machine is designed to form a seam of three-thread overedge chain stitches, comprises a second threaded looper 45 that is secured by a screw 46 to a clamp 47. The screw 46 also extends through a slot in the shank of the looper 45 to provide for radial adjustment of the looper. The clamp 47 has a hub 48 mounted to the end of a looper shaft 49 and split at the end to be clamped to the shaft 49 by a screw 50. The looper shaft 49 is journaled for oscillation in a bushing 51 extending through a bearing lug 52 in the wall 24 of the standard and is arranged preferably in the same horizontal plane as the looper shaft 32 at an acute angie to the axis of the needle bar 22, the shaft 49 being arranged upon the opposite side of the needle bar 22 from the shaft 32 and at nearly a right angle to the shaft 32. The looper shaft 49 is held against endwise sliding in the bushing 51 by a collar 53, which abuts against the outer end of the bushing 51, and the hub of a crank arm 54 which abuts against the inner end of the bushing. The crank arm 54, which is secured to the shaft 49, carries a ball-end crank pin 55 that is connected to one end of a pitrnan 56 having a strap portion at the other end thereof which embraces an eccentric 57 on the main shaft 7.

In the same manner as for the looper 28, means are provided for facilitating adjustment of the looper 45 axially and circularly of the shaft 49, Which means com- 4 prises a collar 58 fixed to the end of the shaft 49 by a set screw 59. The clamp 47 and collar 58 may be individually released from the shaft 49 and adjusted while using the other as a marker from which to gauge the adjustment.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claim.

Having thus set forth the nature of the invention, what I claim herein is:

A looper mechanism for a sewing machine having a frame provided with a looper shaft bearing bushing secured therein, comprising, a looper shaft journaled in said bearing bushing, a retaining collar secured on said looper shaft and bearing against the end of said bearing bushing, an escutcheon element mounted on said bushing and counterborcd to receive and extend beyond said retaining collar, a reference collar slidably mounted on said shaft and having one of its ends extending into the counterbore of said escutcheon, means releasably securing said reference collar in adjusted position on said looper shaft, a looper carrier disposed in face-to-face contact with said reference collar and adjustably mounted on said shaft for sliding movement on said shaft and for circular movement about said shaft, means for securing said looper carrier in adjusted position on said looper shaft, and a looper mounted on said looper carrier.

References Cited in the file of this patent UNITED STATES PATENTS 1,641,135 Clayton Aug 30, 1927 2,224,028 Becker Dec. 3, 1940 2,729,176 Smith Jan. 3, 1956 

